1. Field of the Invention
The present invention relates to field emission devices, and more particularly to a field emission device employing nano material.
2. Description of Related Art
Field emission devices are based on emission of electrons in a vacuum. Electrons are emitted from micron-sized tips in a strong electric field, the electrons are then accelerated and collide with a fluorescent material. The fluorescent material then emits visible light. Field emission devices are thin, light weight, and provide high levels of brightness.
Conventionally, a material of the tips is selected from the group consisting of molybdenum (Mo) and silicon (Si). With the development of nano-technology, carbon nanotubes (CNT) can also used for the tips of the field emission devices. However, typical working voltage of such field emission devices is about 10,000 volts, which creates enough electrostatic force to make break CNTs. As a result, performance of field emission devices may be unstable.
What is needed, therefore, is a field emission device capable of stable operation.